
Powder welding is a process involving the heating of a work piece with the help of a welding torch. At the same time, a dosage of metal powder is induced into the thermal flame. The metal powder then melts and gives a dense coating, which further creates a strong bond with the metal surface or work piece by the means of diffusion and surface alloying. In a powder welding assembly, the hopper is attached to the flame torch where the metal powder is fed. Powder welding is commercially used where a very thin layer of welding is required, particularly for smaller parts. In powder welding, the small thickness of 0.15 mm can give the optimum hardness, which is a prerequisite in many process industries. In the commercial marketplace, numerous metal powders are used in powder welding such as ferrous, nickel, aluminium, silver, copper, and titanium, among others. Also, metal alloys can be used in the powder welding process, and most of them are nickel-based. One of the most common alloys used in powder welding is Ni-B-Si (Nickel-Boron-Silicon), a self-fluxing alloy. The presence of silicon and boron imparts efficient fluidity during the operation, and also helps in reducing the melting points of the powder welding cycle, which further allows powder welding operation at low temperatures. The most common application technique where powder welding is used is oxy acetylene welding, owing to its cost-effective nature. However, powder welding can also be used in other welding techniques. Powder welding is predominantly used in processes where the base material is either iron, copper, or nickel.